MCP23017 PORT EXPANDER ACCESO RASPBERRY PI POR DRIVER

//i2c bus expander mcp23017 with driver ....raspberryPi
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#define GPIO_ADDR 496 // mcp base address
enum dir{IN,OUT};

void gpioExport(int gpio)
{
    int fd;
    char buf[255];
    fd = open("/sys/class/gpio/export", O_WRONLY);
    sprintf(buf, "%d", gpio);
    write(fd, buf, strlen(buf));
    close(fd);
}

void gpioDirection(int gpio, int direction) // 1 for output, 0 for input
{
    int fd;
    char buf[255];
        sprintf(buf, "/sys/class/gpio/gpio%d/direction", gpio);
        fd = open(buf, O_WRONLY);

        if (direction){
        printf ("gpio %d out\n",gpio);
            write(fd, "out", 3);
        }else{
        printf ("gpio %d in\n",gpio);
        write(fd, "in", 2);
    }
        close(fd);
}

void gpioSet(int gpio, int value)
{
    int fd;
    char buf[255];
        sprintf(buf, "/sys/class/gpio/gpio%d/value", gpio);
        fd = open(buf, O_WRONLY);
        sprintf(buf, "%d", value);
        write(fd, buf, 1);
        close(fd);
}

int main (){
    int offset=0;
    do{
        gpioExport(GPIO_ADDR+offset);
        gpioDirection ( GPIO_ADDR+offset ,offset <8 ?IN:OUT);
    }while (GPIO_ADDR+(offset++) <(GPIO_ADDR+15));

    //gpioExport(506);
    //gpioDirection(506,OUT);
    //gpioSet(506,1);

    do {//Set OUTs PORTB MCP23017
        gpioSet(GPIO_ADDR+offset,0);

    }while ((GPIO_ADDR+ (offset--)) >=GPIO_ADDR);

    return 0;
}